


Math for Perverts

by 27dragons, tisfan



Series: MCU Kink Bingo [51]
Category: Captain America (Movies), Iron Man (Movies), Marvel Cinematic Universe, The Avengers (Marvel Movies)
Genre: Bondage, Coming Untouched, Lube, M/M, Nipple Clamps, Nipple Play, Plot What Plot/Porn Without Plot, pouncer wheel
Language: English
Status: Completed
Published: 2018-11-05
Updated: 2018-11-05
Packaged: 2019-08-18 21:06:20
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,068
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16524650
Author URL: https://archiveofourown.org/users/27dragons/pseuds/27dragons, https://archiveofourown.org/users/tisfan/pseuds/tisfan
Summary: Bucky has very, very sensitive nipples. Tony wonders if Bucky came come from nipple stimulation alone.





	Math for Perverts

**Author's Note:**

> what it says on the tin

Tony had sometimes called it math for perverts, the perfect curve and bend he managed to get out of the customizable restraints, the way he could position Bucky exactly as he wanted, allowing sometimes a little -- but never enough -- movement. Or none at all.

The alignment of heavy cuffs, designed to contain Bucky’s serum-enhanced strength, and the metal arm, should not have been sexy, but when Tony had a few captured images projected, Bucky had to admit, he looked… delicious. Helpless. Arms bent at the elbow and secured behind his back in a way that thrust his chest forward, knees spread so he couldn’t get any friction, beyond what Tony allowed, and throat collared. The position that allowed him to keep breathing meant his head was tipped all the way back, his hair a waterfall down his back.

The last buckle fastened, and Tony stood there, admiring his handiwork, and keeping his hand on Bucky’s shoulder, letting him relax into the position. Not that relaxing was exactly what he could do -- it wasn’t very comfortable, but it wasn’t meant to. Part bondage, part trust issue. It took him several deep breaths, released in gradually slower bursts, until he eased into acceptance, the whole time not being able to take his eyes off the photo captures; the way he looked.

The way Tony looked, when he gazed at Bucky, bound, helpless, _on display_.

Under the frisson of nerves, the heat in his belly that accompanied a scene, was the deep kernel of humiliation, just enough to keep him from total compliance. He shook his head, felt the tickle of hair down his back and over his wrists. Closed his eyes.

Breathed.

Tony would know, when Bucky was ready.

He always did.

“That’s it,” Tony soothed, his thumb rubbing gently on Bucky’s shoulder. “I’ve got you. Just relax.” The hand lifted briefly, stroked down Bucky’s cheek. “Everything feel okay? Not too tight? You can breathe?”

“S’long as I stay still,” Bucky told him with a wry tip of his mouth. They both knew that Bucky didn’t do _still_ any better than Tony did. He licked his lip nervously, then settled again. “I’m green. Sir.”

“That’s a good boy,” Tony said. He bent over to kiss Bucky, licking at the edges of Bucky’s lips, teasing the sensitive corners. “Oh, I’m going to have so much fun with you.” He trailed a hand down Bucky’s throat and chest, flicked his thumb across Bucky’s nipples.

Tony always did; he was endlessly inventive, wringing as much pleasure from Bucky as he could manage. Bucky was the first to admit that sometimes, slower was better, enjoying each sensation and the ache of need, but at the same time, Bucky was like a starving man at a buffet, taking as much as he could get, greedy and heedless, just wanting it because he _could_.

As always, the sensation of Tony’s hands on him was enough to swirl the lust in Bucky’s blood, make his heart beat just a little faster. He squirmed as Tony brushed light, down his chest, a flutter of touch, not nearly enough, soft and almost tickly.

“All right, sweetheart, let’s move on to part two, shall we?” Tony pulled back a little, reaching for the toybox he’d left out for Bucky to eye during the initial setup. He held up a little golden clamp where Bucky could see it. “What do you think? Pretty, hm?” He flicked his thumb across Bucky’s nipple again, pinched it until it drew up taut, and then carefully put the clamp on it. “Oh, yeah, that’s gorgeous.”

Bucky inhaled as his nipple pebbled. A sharp sting that sent bolts of heat through his whole chest, and then it _throbbed_. The clamp held that tender skin, tight, and the sharpness faded, but it wouldn’t quite stop. The twinge of pain shifted to pleasure, back to pain, an endless push-pull that nearly had him gasping. His other nipple prickled and tightened, as if in self-defense or sympathy.

“You like that?” Tony asked. He held up another clamp, smirking. He leaned down to flick his tongue, warm and wet, over Bucky’s other nipple, before setting the second clamp. “Oh, yes, that’s pretty.”

There was just enough give and wiggle room in the restraints for just that -- wiggling. Which Bucky did. Experimentally at first, and then as the clamps tightened, it devolved into squirming and all the way to writhing. Bucky opened his mouth and a soft whimper came out. He always knew he was sensitive; moreso after the serum. Tony sometimes enjoyed tweaking him, on the sly, just to watch Bucky struggle to act normal during movie nights.

“ _Jesus_ ,” he finally said, getting himself back under control.

Tony grinned at him. “Oh, yes, you like that, don’t you.” He examined Bucky’s face minutely, then took hold of a clamp and twisted it, just a little, sending a fresh jolt of pain/pleasure lancing through Bucky’s chest. “I do love your sensitivity,” he admitted. “I thought we’d have a little fun with it today, see just how far we can push it.” He stroked a hand through Bucky’s hair and leaned close. “I think you could come just from me playing with your nipples,” he confided.

Bucky's eyes sprang open as if on springs. “Seriously?” he croaked. He shuddered, the motion sending more bolts of electric need through him.

“Seriously,” Tony said. “I mean, it’s just a theory right now. It needs to be tested, don’t you think? I hate not knowing things. And I love watching you squirm. So win-win, really.”

“ _Science_ for perverts,” Bucky chuckled weakly, his stomach doing flips just _thinking_ about it. He strained, accidentally and unconsciously throttling himself until he remembered and eased back into position. “God, you’re mean. Sir.”

“Only because you enjoy it so much,” Tony said. He tweaked both clamps this time. “Well, and because I _do_ enjoy a challenge. Want to find out what else is in my goodie box?”

“And because you’re a sadist,” Bucky snorted, craning his head. It always had to start that way; by the end of whatever Tony had planned for him, Bucky would be whining, begging, sometimes even sobbing, but it always started out with sarcasm. He could not actually see in the box, and rather suspected that Tony knew that. Anticipation was part of the charm.

“Oh, well, if you want to skip straight to the sadism,” Tony said gleefully, “I can certainly oblige.” He made a show of rummaging in the box, letting Bucky hear things shifting around, the click of plastic and the clink of metal and the soft whisper of fabric. He held up an instrument that certainly _looked_ like it was designed for torture, a small wheel of wicked-looking spikes, not unlike a boot-spur, attached to a handle. “Useful for tracing patterns,” Tony told him. “It has medical purposes as well. What do you think?” He didn’t wait for Bucky to answer before rolling it lightly across Bucky’s pectoral, an inch or so above his nipples. “Interesting sensation, right?”

_Interesting_ was a word. Bucky hit the collar again, trying to see, trying to look, goddamnit. It was like-- being scratched with a pin, of hitting the brambles on a rosebush, little tiny prickles. It didn’t last enough to actually hurt, not even on Bucky’s sometimes oversensitive skin, but it left a line of speckled heat behind. It made him want to scratch at his chest in the worst way, too. And then Tony blew a line of cool air over it, which made the whole thing flare up.

He tried to imagine what that sensation would be like over his nipples, that flame and ice and itch. He was pretty sure it wouldn’t take long before he had to imagine it, but he couldn’t help it. His belly clenched up, and his dick jerked, muscles spasming hectically.

“Yes, sir,” Bucky said, because Tony liked to be answered when he asked a question, even if it was rhetorical.

“Good boy,” Tony said warmly, granting Bucky another warm kiss. “Are we still green, soldier?”

There was always going to be the part of Bucky that got all conflicted whenever Tony asked that; first off, did Tony actually think that Bucky was, what? A crybaby? That he couldn’t take whatever Tony dished out, and for that matter, quite a bit more. And the part that desperately wanted to code out, just to see if he _could_. Just to find out if he was actually allowed to.

Add to that, a third part that always, always wanted to see where Tony was going with --whatever it was that he was doing.

Bucky took a breath to consider it. “I’m green, sir.”

“Very good, thank you, sweetheart.” Tony kissed him again. Then he stepped back -- not far; Bucky could still hear his breathing, a soft, considering hum. Then that gentle prickle was back, rolling around Bucky’s torso aimlessly. Around his nipples, but not quite touching the areolas. Down and across his stomach. Over the curve of his hips. Back up to his chest.

Without warning, one of the clamps disappeared, blood rushing back into the area with a sudden flood of heat. When the prickles ran over the area this time, they felt like tiny fires under his skin.

Bucky’s jaw clenched up around a sudden, wanton moan. It was good, bad. Horribly wonderful. He couldn’t decide, and he shook his head back and forth, shifted his arms, trying to pull away, and all it did was puff his chest out more, make him more of a target for that-- Christ, that thing was _wicked_. The other nipple, still clamped, throbbed harder, like it was waiting its turn.

Tony leaned over to examine him again. “You’re fighting it,” he observed idly. “Have to let it go, snowflake.” Another line of prickles, a little harder this time. “You know I’m going to get those lovely noises out of you eventually.”

Bucky panted for air. “You wouldn’t like it so much if I didn’t--” inhale, exhale, he knew how to fucking breathe, thank you “-- make you work for it.” He rolled his eyes. “Sir.” He wasn’t feeling quite cheeky enough to go on to full disrespect, not with Tony and that damn torture wheel of his right there in his face. Not yet. He’d probably get there, though.

“Make _you_ work for it, you mean,” Tony said. “But if you’re ready to kick things up a notch, all you had to do was ask.” He reached for something else. Didn’t show it to Bucky this time. Bucky heard a quiet click, and then Tony was smearing something over his unclamped nipple. Lotion? Tony bent down to blow gently across it, and Bucky was ready for the cool rush of air, but not for the heat that followed in its wake.

“Aaah!” Bucky hissed like he’d just taken a slug of molten coffee without thinking to let it cool off. It burned, like the time they’d tried candle wax, although that was splatters that had cooled after a moment of sizzling sensation. This just… kept burning. His nerves all checked in, reporting on the fire that was apparently contained just to his right nipple. “Oh, my god, Tony, Tonytonytony, oh, my god!” He was babbling, he knew he was, and instead of pulling back, he pushed forward, aching for some relief. “Please, please, sir--”

“I know, it’s absolutely devilish, isn’t it?” Tony scattered soft kisses down Bucky’s throat, a sweet contrast that did nothing to distract Bucky from the sensations in his chest. “Mm, you do look a little off-center, though. Can’t have that.” The clamp was back on his nipple, its weight a relief and a torture.

Tony tugged gently at the left-side clamp, waking nerves that Bucky had almost forgotten in the face of the fire on the right. A finger trailed down his chest. “Look at that pretty flush spreading. Are you having fun, sweetheart?”

It was, Bucky had noticed this before, a little difficult to give Tony the full weight of his murder stare when he was bent backward. “Might be,” he admitted, and even that much was hard to do, “might like it more if your mouth was on me. Sir.”

“Oh, you want my mouth, do you? Well, it’s hard to say no to that, especially when you look so delicious.” Tony knelt in front of him and then the wet heat of Tony’s mouth was engulfing Bucky’s left nipple, that clever tongue flicking at the clamp, jostling it in place. “Like that, soldier? That what you wanted?”

It hadn’t been what he’d _intended_ ; Bucky had to be careful with Tony, all the time. That quick mind of his jumped through loopholes like a constitutional lawyer. But oh, oh, oh fuck, he’d take it. Around the little jolts of pain, of straight up torture, Tony’s mouth was soft, and it was slick and wet, and the tip of his tongue was glorious. He couldn’t push himself into it any more than he already was, his back aching from holding the curve, throat at the very edge of his collar. He straight up whined, wordlessly begging Tony to keep doing that, oh, that, just-- “ _Christ_.”

“Oh, he likes it,” Tony purred. His tongue flicked over the right side, the heat of Tony’s breath reigniting the fire, coaxing it to fresh heights. “Mm, butterscotch.” Then he returned to the left, teasing and sucking still more, rewarding each groan and whimper with a new torment.

He tugged the clamp free and Bucky nearly shouted as Tony sucked hard, teeth scraping delicately over the abused skin. “That’s it, baby,” Tony murmured between licks. “Give it up to me, give it all up.”

Each lick, each twist and pull, the scrape of Tony’s teeth was a delectable ache. He wasn’t sure how long they stayed like that, pulled in that taffy-candy moment where time didn’t mean anything, but Bucky was whimpering with each breath, hips moving fruitlessly for some pressure, some friction, something-- His skin was slick with sweat, chilled and heated at the same time, and oh, oh, god, he _wanted_.

Every nerve ending in his body was on fucking fire; he shivered with waves of hot and cold, and everything kept built up, nerves ratcheted higher with each movement, until Bucky was begging, pleading, needing it so badly that it hurt, and needing the hurt so bad it was ecstacy. Tony had said, he’d said, he was going to see, he was going to try, could Bucky come, just from this, even though there was nothing _just_ about it. He was pretty sure he couldn’t; he needed, oh, Christ, he needed, but Tony wasn’t going to give it to him. Tony was going to make him try, at least, or he was just going to keep _teasing_.

Bucky went limp in his bindings, head no longer straining, just letting it happen. He couldn’t, he didn’t think he could, he was pretty fucking sure he needed-- Tony’s hands ran lightly down his ribs, across his hips. Bucky’s hips jerked, helpless to resist. Just a little touch, a little one, just a brush and he’d go off like a firecracker, but--

“I can’t,” Bucky whined, and despite that, his body was still straining for it, still pushing him. He was so close, every muscle tight, so tight, his breathing was stuttering, stopping, heart pounding so hard his eyes ached. “Tony-- Tony-- I--”

Bucky gritted his jaw, clenching down on a scream, like he was trying to lift a car with just his mind. Holy hell.

“I know, baby, I know, you’re doing so well, you’re so beautiful, so brave, so perfect for me.” Tony nuzzled at the underside of Bucky’s jaw, even as his hands kept up that torment, pinching and stroking and twisting. “I don’t have any words for it, sweetheart, you’re so, so gorgeous like this. You’re such a gift.” His breath was hot against Bucky’s ear. “Let go, honey, just fall and let me catch you.”

It was always that whisper thin moment, that snap like a scrim of ice on a puddle, that sense that Tony would always, always be there for him, and who the fuck was he trying to fool. He would always do whatever Tony wanted of him, whenever Tony wanted it. Because Tony had been the one to catch him, and hold him up. He pushed himself up to the edge, because Tony wanted it, and Bucky wanted to give it to him.

_What if I fall?_

_Darling, what if you fly?_

Bucky screamed, and the scream broke into ragged sobs and everything in him clenched to the point of white hot agony before letting go. Pleasure, from the release, was second only to the rush of heat in Tony’s eyes, the way his mouth dropped open, the way love and pride and fierce possession were stamped across those much beloved features. “Oh, oh, god.”

“Oh, baby, you’re so _perfect_ ,” Tony groaned. He kissed Bucky, again and again, passionate and scalding. His hands petted over Bucky’s hair and shoulders and skin, soothing. “That was amazing, that was _glorious_ , oh honey, you’re too good to me.” He unbuckled the collar and slipped his hand to the back of Bucky’s neck, helping to lift his head after keeping it tipped back for so long. “There you go. How are you feeling, sweetheart?”

Bucky panted for air, just breathing, just looking at Tony, sweet and perfect and much loved. “Oh, I’m good,” he whispered, more than said. “I’m… yeah, so good.” He tipped his cheek, brushing it against Tony’s palm, a brief caress. “Love you.”

Tony’s smile could have lit up the room. “Love you too, honey.” He pressed a kiss to Bucky’s forehead, nuzzled down Bucky’s temple. “So much. Give me just a minute to get you out of all this, and then we’ll go get you cleaned up, hm?”

Everything was soft, nice. Kinda shiny. Like being wrapped in thick fog on a bright summer morning, sunlight reflecting on each drop of suspended water. Burst into a million soap bubbles. Bucky nodded. “Yeah, yeah, that’s… that’s good, baby, that’s just… fine.” He let himself sink into it, the softness. Tony was strong and Bucky didn’t have to be. Not all the time. Sometimes, sometimes he could let Tony hold him up.

 


End file.
